blob: 23d5860f5481f204a257ae6e9dab72450fb651fe [file] [log] [blame]
// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package source provides core features for use by Go editors and tools.
package source
import (
"bytes"
"context"
"go/format"
"golang.org/x/tools/internal/imports"
"golang.org/x/tools/internal/lsp/diff"
"golang.org/x/tools/internal/lsp/protocol"
"golang.org/x/tools/internal/span"
"golang.org/x/tools/internal/telemetry/trace"
errors "golang.org/x/xerrors"
)
// Format formats a file with a given range.
func Format(ctx context.Context, view View, f File) ([]protocol.TextEdit, error) {
ctx, done := trace.StartSpan(ctx, "source.Format")
defer done()
snapshot, cphs, err := view.CheckPackageHandles(ctx, f)
if err != nil {
return nil, err
}
cph, err := NarrowestCheckPackageHandle(cphs)
if err != nil {
return nil, err
}
pkg, err := cph.Check(ctx)
if err != nil {
return nil, err
}
ph, err := pkg.File(f.URI())
if err != nil {
return nil, err
}
// Be extra careful that the file's ParseMode is correct,
// otherwise we might replace the user's code with a trimmed AST.
if ph.Mode() != ParseFull {
return nil, errors.Errorf("%s was parsed in the incorrect mode", ph.File().Identity().URI)
}
file, m, _, err := ph.Parse(ctx)
if err != nil {
return nil, err
}
if hasListErrors(pkg) || hasParseErrors(pkg, f.URI()) {
// Even if this package has list or parse errors, this file may not
// have any parse errors and can still be formatted. Using format.Node
// on an ast with errors may result in code being added or removed.
// Attempt to format the source of this file instead.
formatted, err := formatSource(ctx, snapshot, f)
if err != nil {
return nil, err
}
return computeTextEdits(ctx, view, ph.File(), m, string(formatted))
}
fset := view.Session().Cache().FileSet()
buf := &bytes.Buffer{}
// format.Node changes slightly from one release to another, so the version
// of Go used to build the LSP server will determine how it formats code.
// This should be acceptable for all users, who likely be prompted to rebuild
// the LSP server on each Go release.
if err := format.Node(buf, fset, file); err != nil {
return nil, err
}
return computeTextEdits(ctx, view, ph.File(), m, buf.String())
}
func formatSource(ctx context.Context, s Snapshot, f File) ([]byte, error) {
ctx, done := trace.StartSpan(ctx, "source.formatSource")
defer done()
data, _, err := s.Handle(ctx, f).Read(ctx)
if err != nil {
return nil, err
}
return format.Source(data)
}
// Imports formats a file using the goimports tool.
func Imports(ctx context.Context, view View, f File) ([]protocol.TextEdit, error) {
ctx, done := trace.StartSpan(ctx, "source.Imports")
defer done()
_, cphs, err := view.CheckPackageHandles(ctx, f)
if err != nil {
return nil, err
}
cph, err := NarrowestCheckPackageHandle(cphs)
if err != nil {
return nil, err
}
pkg, err := cph.Check(ctx)
if err != nil {
return nil, err
}
if hasListErrors(pkg) {
return nil, errors.Errorf("%s has list errors, not running goimports", f.URI())
}
ph, err := pkg.File(f.URI())
if err != nil {
return nil, err
}
// Be extra careful that the file's ParseMode is correct,
// otherwise we might replace the user's code with a trimmed AST.
if ph.Mode() != ParseFull {
return nil, errors.Errorf("%s was parsed in the incorrect mode", ph.File().Identity().URI)
}
options := &imports.Options{
// Defaults.
AllErrors: true,
Comments: true,
Fragment: true,
FormatOnly: false,
TabIndent: true,
TabWidth: 8,
}
var formatted []byte
importFn := func(opts *imports.Options) error {
data, _, err := ph.File().Read(ctx)
if err != nil {
return err
}
formatted, err = imports.Process(ph.File().Identity().URI.Filename(), data, opts)
return err
}
err = view.RunProcessEnvFunc(ctx, importFn, options)
if err != nil {
return nil, err
}
_, m, _, err := ph.Parse(ctx)
if err != nil {
return nil, err
}
return computeTextEdits(ctx, view, ph.File(), m, string(formatted))
}
type ImportFix struct {
Fix *imports.ImportFix
Edits []protocol.TextEdit
}
// AllImportsFixes formats f for each possible fix to the imports.
// In addition to returning the result of applying all edits,
// it returns a list of fixes that could be applied to the file, with the
// corresponding TextEdits that would be needed to apply that fix.
func AllImportsFixes(ctx context.Context, view View, f File) (edits []protocol.TextEdit, editsPerFix []*ImportFix, err error) {
ctx, done := trace.StartSpan(ctx, "source.AllImportsFixes")
defer done()
_, cphs, err := view.CheckPackageHandles(ctx, f)
if err != nil {
return nil, nil, err
}
cph, err := NarrowestCheckPackageHandle(cphs)
if err != nil {
return nil, nil, err
}
pkg, err := cph.Check(ctx)
if err != nil {
return nil, nil, err
}
if hasListErrors(pkg) {
return nil, nil, errors.Errorf("%s has list errors, not running goimports", f.URI())
}
options := &imports.Options{
// Defaults.
AllErrors: true,
Comments: true,
Fragment: true,
FormatOnly: false,
TabIndent: true,
TabWidth: 8,
}
importFn := func(opts *imports.Options) error {
var ph ParseGoHandle
for _, h := range pkg.Files() {
if h.File().Identity().URI == f.URI() {
ph = h
}
}
if ph == nil {
return errors.Errorf("no ParseGoHandle for %s", f.URI())
}
data, _, err := ph.File().Read(ctx)
if err != nil {
return err
}
fixes, err := imports.FixImports(f.URI().Filename(), data, opts)
if err != nil {
return err
}
// Apply all of the import fixes to the file.
formatted, err := imports.ApplyFixes(fixes, f.URI().Filename(), data, options)
if err != nil {
return err
}
_, m, _, err := ph.Parse(ctx)
if err != nil {
return err
}
edits, err = computeTextEdits(ctx, view, ph.File(), m, string(formatted))
if err != nil {
return err
}
// Add the edits for each fix to the result.
editsPerFix = make([]*ImportFix, len(fixes))
for i, fix := range fixes {
formatted, err := imports.ApplyFixes([]*imports.ImportFix{fix}, f.URI().Filename(), data, options)
if err != nil {
return err
}
edits, err := computeTextEdits(ctx, view, ph.File(), m, string(formatted))
if err != nil {
return err
}
editsPerFix[i] = &ImportFix{
Fix: fix,
Edits: edits,
}
}
return nil
}
err = view.RunProcessEnvFunc(ctx, importFn, options)
if err != nil {
return nil, nil, err
}
return edits, editsPerFix, nil
}
// AllImportsFixes formats f for each possible fix to the imports.
// In addition to returning the result of applying all edits,
// it returns a list of fixes that could be applied to the file, with the
// corresponding TextEdits that would be needed to apply that fix.
func CandidateImports(ctx context.Context, view View, filename string) (pkgs []imports.ImportFix, err error) {
ctx, done := trace.StartSpan(ctx, "source.CandidateImports")
defer done()
options := &imports.Options{
// Defaults.
AllErrors: true,
Comments: true,
Fragment: true,
FormatOnly: false,
TabIndent: true,
TabWidth: 8,
}
importFn := func(opts *imports.Options) error {
pkgs, err = imports.GetAllCandidates(filename, opts)
return err
}
err = view.RunProcessEnvFunc(ctx, importFn, options)
if err != nil {
return nil, err
}
return pkgs, nil
}
// hasParseErrors returns true if the given file has parse errors.
func hasParseErrors(pkg Package, uri span.URI) bool {
for _, err := range pkg.GetErrors() {
if err.URI == uri && err.Kind == ParseError {
return true
}
}
return false
}
func hasListErrors(pkg Package) bool {
for _, err := range pkg.GetErrors() {
if err.Kind == ListError {
return true
}
}
return false
}
func computeTextEdits(ctx context.Context, view View, fh FileHandle, m *protocol.ColumnMapper, formatted string) ([]protocol.TextEdit, error) {
ctx, done := trace.StartSpan(ctx, "source.computeTextEdits")
defer done()
data, _, err := fh.Read(ctx)
if err != nil {
return nil, err
}
edits := view.Options().ComputeEdits(fh.Identity().URI, string(data), formatted)
return ToProtocolEdits(m, edits)
}
func ToProtocolEdits(m *protocol.ColumnMapper, edits []diff.TextEdit) ([]protocol.TextEdit, error) {
if edits == nil {
return nil, nil
}
result := make([]protocol.TextEdit, len(edits))
for i, edit := range edits {
rng, err := m.Range(edit.Span)
if err != nil {
return nil, err
}
result[i] = protocol.TextEdit{
Range: rng,
NewText: edit.NewText,
}
}
return result, nil
}
func FromProtocolEdits(m *protocol.ColumnMapper, edits []protocol.TextEdit) ([]diff.TextEdit, error) {
if edits == nil {
return nil, nil
}
result := make([]diff.TextEdit, len(edits))
for i, edit := range edits {
spn, err := m.RangeSpan(edit.Range)
if err != nil {
return nil, err
}
result[i] = diff.TextEdit{
Span: spn,
NewText: edit.NewText,
}
}
return result, nil
}